Sprinkler head riser mechanism

ABSTRACT

A riser mechanism for a lawn sprinkler head which includes a head-bearing riser tube telescoped for vertical adjustment within a stationary supply tube disposed underground, a spiral spring is longitudinally disposed in the stationary tube and the telescoping tube has a radial projection engageable with the threads provided by the spring. Rotation of the riser tube causes extension or retraction of the riser tube relative to the stationary tube. The upper end of the stationary tube is provided with a sleeve nut which has an inner surface engageable with the thread engaging projection of the riser tube to thereby prevent axial removal of the riser tube out of the stationary tube, and the upper end of the spring deflects to prevent jamming of the projection against the under-surface of the nut.

United States Patent Fischer et al.

[451 Aug. 15,1972

[54] SPRINKLER HEAD RISER MECHANISM [72] Inventors: Edward Fischer,Saline; William J.

Trickey, East Lansing, both of Mich.

[73] Assignee: Superior Pipe Specialties Company,

Chicago, lll.

[22] Filed: Dec. 16,1970

[21 Appl. No.: 98,608

[52] US. Cl ..239/203, 239/587 [51] Int. Cl ..B05b 15/10, B05b 15/08{58] Field of Search ..239/203, 204, 205, 587

[56] References Cited UNITED STATES PATENTS 2,315,911 4/1943 Truedson..239/205 3,118,609 l/1964 Glover ..239/205 Primary ExaminerM. HensonWood, Jr. Assistant Examiner-Edwin D. Grant AttorneyCullen, Settle,Sloman & Cantor 5 7] ABSTRACT A riser mechanism for a lawn sprinklerhead which includes a head-bearing riser tube telescoped for verticaladjustment within a stationary supply tube disposed underground, aspiral spring is longitudinally disposed in the stationary tube and thetelescoping tube has a radial projection engageable with the threadsprovided by the spring. Rotation ofthe riser 'tube causes extension orretraction of the riser tube relative to the stationary tube. The upperend of the stationary tube is provided with a sleeve nut which has aninner surface engageable with the thread engaging projection of theriser tube to thereby prevent axial removal of the riser tube out of thestationary tube, and the upper end of the spring deflects to preventjamming of the projection against the under-surface of v the nut.

3 Claims, 3 Drawing Figures SHEEI10F2 PATENTEDAus 15 m2 INVENTORSWILLIAM J. TRICKE). BY EDWARD FISCHER. CULLEN, SETTLE, SLOMAN a CANTORATT'YS PATENTED l9?2 3.684.179

SHEEI 2 0F 2 IN VE N TORS WILLIAM JJRICKEY. EDWARD FISCHER.

CULLEN, SETTLE, SLOMAN aCANTm ATT'YS.

SPRINKLER HEAD RISER MECHANISM BACKGROUND AND SUMMARY OF THE INVENTIONThe present invention relates to lawn sprinkler systems and more inparticular to an improved riser mechanism for a sprinkler head thereofto adjust the sprinkler head support member relative to the groundsurface.

It is known in underground installed lawn sprinkler systems to support aplurality of sprinkler head supports on vertical pipes extending fromthe main water supply lines below the ground. The sprinkler head supportmembers and associated water conduits extend from the underground watersupply pipes upwardly to the ground surface along which they must beretained in a flush position with the surface to permit lawn maintenanceequipment to pass thereover without being obstructed.

Different portions of lawn or turf surfaces are not always on the samelevel, requiring some sort of adjustment relative to the undergroundmain water supply lines which are disposed at a certain fixed depthbelow the ground surface During and after installation of undergroundlawn sprinkler systems in established lawsn, re-sodding of the lawnaround the sprinkler heads usually result in a change of height leveldifferent from the established level of the lawn priorto installation ofthe system on which the installation and depth positioning of theunderground pipes was based. This requires individual height adjustmentof the several sprinkler head support members to compensate for thechange in ground level. Such height adjustment may be necessary severaltimes after the re-sodded lawn settles around the sprinkler heads toprevent the top surface of the sprinkler head support member fromextension above the ground level.

Conventionally, adjustable lawn sprinkler head conduits are made of twotube sections threaded within each other for vertical adjustment of theupper tube section which supports the sprinkler head relative to thelower, stationary tube section which is attached to the main watersupply pipe in the ground. Adjustment is made by relative rotation ofthe upper tube section for threading it in or out of the lower tubesection.

This conventional arrangement is objectionable in that the exposedthreads easily contaminate and corrode at a fast rate, making futurevertical adjustment difficult, if not impossible. Secondly, conventionalpipe or tube threads require an excessive number of revolutions toaccomplish the substantial vertical adjustments which are commonlyrequired.

A further drawback of the conventional, screw-type sprinkler headadjustment resides in the fact that continued vertical adjustment simplycompletely disconmeets the upper tube section and sprinkler head fromthe lower tube section. A number of thefts of expensive sprinkler headshave occurred. Any attempt to limit the extent of adjustment ofconventional threaded tubes simply results in jammed or strippedthreads, ruining the installation and requiring replacement.

The present invention provides an improved adjustable riser mechanismfor a lawn sprinkler head which eliminates the above disadvantages ofconventional riser mechanisms of this type.

Accordingly, the primary object of the present invention is to providean adjustable riser mechanism for a lawn sprinkler head which comprisestelescopically extendable tube sections incorporating thread engagingmeans independent of the tube sections, for vertical rotatableadjustment of the upper tube section which supports the sprinkler head.

A further object of the present invention is to provide meansincorporated into the present improved riser mechanism to preventcomplete threaded disconnection of the upper tube section from the lowertube section and to thereby prevent the removal thereof by unauthorizedpersons, while preventing thread damage and providing a quicklyadjustable, long lead thread.

The present invention will be best understood by reference to thefollowing detailed description in connection with the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate apreferredembodiment in which:

FIG. 1 is a composite schematic illustration of an underground sprinklersystem embodying the present improved riser mechanism illustratedtherein in normal and in adjusted position and having portions thereofbroken away for illustration of portions of the internal structurethereof; I

FIG. 2 is an enlarged vertical section through the riser mechanismillustrated in FIG. 1; and

FIG. 3 is a transverse enlarged cross-section through the improved risermechanism illustrated in FIG. 2 as seem along line 3-3 thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT With continuous reference to thedrawings in FIG. 1,

- a representative underground lawn sprinkler system is shown installedin a lawn having a top surface 10. The main water supply pipe 12 isinstalled in the ground 11 at a certain fixed depth from the top surface10. The main water supply pipe 12 has a plurality of branch connectors14 located at spaced intervals therealong for the attachment of upwardlyextending sprinkler head conduit assemblies 16, communicating with thepipe 12.

The vertical conduit assemblies 16 normally are attached at the upperend to a sprinkler head support member 18 which supports a sprinklerhead 20. The sprinkler head 20 may be of any conventional type,

' such as of the pop-up and/or rotatable type, and per se forms no partof the present invention.

The sprinkler head support member 18 normally has a top plate 24 which,when the system is properly installed, is adapted to be substantiallyflush with the lawn surface 10 so as not to provide an obstruction.

The lawn surface 10 around the plurality of individual sprinkler headconduit assemblies 16 (only two of which are shown in FIG. 1) may not beon a common level throughout, but instead around any one of thesprinkler head conduit assemblies 16 the lawn surface 10 may be higherthan at other points, as indicated at the right in FIG. 1, requiringvertical upward adjustment of the sprinkler head conduit assembly 16relative to the stationary underground main water supply pipe 12, asshown.

Likewise, of course, the ground surface around any one sprinkler headconduit assembly 16 may be lower than the remainder of the lawn surfacein which case, of course, the conduit assembly 16 must be adjustedvertically downwardly relative to the stationary water supply pipe 12.

In accordance with the present invention, the sprinkler head conduitassembly 16 embodies the present improved riser mechanism to verticallyadjust the sprinkler head support member 18 so that the top plate 22will be maintained flush with the ground surface at any ground level.

The conduit assembly 16 is composed of outer tube section 24 having athreaded end portion'26 for attachment to the connector 14. The threadedportion 26 further provides a threaded engagement with a sleeve type nut28 which has a skirt portion 30 for extension over the end of the outertube. The nut 28 may be integral with the lower end of the outer tube 24or may be separate therefrom and integral with the threaded portion 26in which instance, the lower end of the outer tube 24 is supported withthe skirt portion 30 of the nut 28.

The upper end of the outer tube 24 is threaded to receive a similarsleeve type nut 32 having a skirt portion 34 for extension around theupper end of the outer tube 24.

The outer tube 24 retains a screw member 38 longitudinally disposedtherein substantially along the entire length of the tube. The screwmember 36 is in the form of a helical compression spring and may besecurely attached internally of the tube 24 at the lower end thereofby'welding, as at 37, or by any conventional securing means known in theart. Alternatively, the spring may be retained in the tube 24 by thesurface friction therebetween, e.e., the relaxed exterior diameter ofthe spring may be greater than the interior diameter of the tube.

The head of the upper sleeve type screw member 32 is axially bored inalignment with the internal bore of the outer tube 24 in order toreceive an inner tube member 38 for telescopic support within the outertube 24. The inner, telescoping tube 38 is provided with a threadedportion 40 at its upper end for threaded locking engagement with thesprinkler head support member 18 which is supported thereon.

It will be understood, that the axial bore of the inner tube 38communicates with the sprinkler head through the sprinkler head supportmember 18 to permit fluid communication from the water supply pipe 12 tothe sprinkler head.

The lower end of the inner tube 38 is provided with a pin 42 extendingradially therethrough in diametrical direction for extension outwardlythereof at both sides of the tube. It will be noted that the pin 42 maybe slightly angularly inclined relative to the central axis of the tube38 for a purpose to appear. The outer end of the pin 42, in assembly, isadapted to be in engagement between adjacent coils of the spring 36. Thedirection of inclination of the pin 42 is in opposite direction to thehelical angle of the coils of the spring 36. Thus, the coil of thespring 36, in effect, provides a female thread member whereas theopposite outer ends of the pin 42 provide a male thread member forthreading engagement with the coils of the spring 36. It will beunderstood, that instead of a continuous pin such as 42, separateabutments may be provided and secured to the outside of the tube 38 onboth sides and in proper position corresponding to the position of theopposite outer ends of the pin 42, or integral projection may be formedon the tube 38 for engagement with the spring 36.

Thus, in order to vertically adjust the sprinkler head support member18, the support member 18 is rotated in the desired direction bycustomarily engaging a tool with the ground plate 22. Rotation of thesupport member 18 rotates the inner tube 38 in the same direction,causing either outer end of the pin 42 to ride up or down (depending ondirection of rotation) along the spiral coils of the spring 36, therebyvertically displacing the tube 38 relative to the outer tube 24. Uponattempted vertical removal of the inner tube 38, the pin 42 simplydeflectsdownwardly and rides over the free upper end of the spring 36.

The upper sleeve type nut member 32 provides an inner redial flange 33which effectively prevents complete disconnection of the inner tube 38from the outer tube 24 when the pin 42 reaches the upper end of thecoils of the spring 36. Thus, since the upper sleeve type nut member 32,in installation, is disposed a considerable distance below the groundsurface 10 and embedded within the ground, unauthorized removal of theriser and sprinkler head assembly 18,20 and tube 38 is not possible,unless the ground is dug up around the sprinkler head to get to the nutmember 32, which must be unscrewed first from the outer tube 24 (whichis likewise embedded in the ground) to permit removal of the completedsprinkler head and riser assembly.

The upper sleeve type nut member 32 also retains a sealing assembly 44comprised of a ring member 46 adapted for abutment circumferentiallyaround the upper edge of the outer tube 24 to provide a sealing surfacefor an associated O-ring 48 disposed circumferentially around the innertube 38. Thus, when the sleeve type nut member 32 is tightened upon thethreaded upper end of the outer tube 24, the sealing as sembly 44 iscompressed in sealing contact to provide an effective seal between theupper end of the outer tube 24 and the nut member 32 to prevent theentrance of moisture of contaminants into the outer tube 24 forprotection of the riser mechanism against contamination and corrosion.If desired, a similar sealing arrangement may be provided at the lowerend of the outer tube 24 in conjunction with the lower nut member 38.

The resilient female thread member 36 is unattached at its upper end andthus, by virtue of engagement of the pin 42 with the coils of the spring36, a slight vertical flexibility of the sprinkler head assembly isprovided for so that, if the top plate 22 should project slightly abovethe ground surface 10 or the ground surface immediately around thesprinkler head is not solid enough, the sprinkler head support member 18is able to be resiliently displaced downwardly if a load is placedthereon by walking thereover or by contact with lawn maintenancemachinery. Thus, there is provided an additional advantageous featureincorporated in the present improved riser mechanism which effectivelyprevents damage to the sprinkler head when contacted by machinery orother means, by being able to be flexibly depressed downwardly andthereafter resume its position when the load is removed.

The spring 36 has other functional advantages as the thread-definingmember. For example, the spring can deflect from its normal cylindricalconfiguration and the outer tube 24 can be formed of a non-rigidmateria1, such as rubber or plastic. This makes possible the provisionof adjusting threads within a flexible hose, the spring also preventscollapsing or kinking of the hose at its curved portion. The spring alsoresiliently collapses and extends to serve as a damping means,preventing hammering in the system when it is suddenly turned on. Theresultant surge of water under pressure against the sprinkler headmerely deflects the spring coils. The prevention of damage to the systemwill be appreciated.

It will be evident from the foregoing description, in conjunction withthe illustrations in the drawings, that the present invention providesan improved riser mechanism for a sprinkler head, which is relativelysimple in structure, easy to assemble and of low cost and is highlyeffective as a screw type vertical adjustment mechanism without theinherent disadvantages of conventional riser mechanisms of this type.

- The wear characteristic of the present riser mechanism is relativelylow and, by provision of the improved sealing arrangement, the mechanismis completely protected against contamination and corrosion.

The primary feature of the present improved riser mechanism consist inthe fact that the sprinkler head and riser assembly cannotbe removedfrom its underground connection without digging up the ground around thesprinkler head, to therefore provide an effective theft preventionmeans.

Furthermore, by the use of the flexible thread member, incorporated inthe present improved riser mechanism, the sprinkler head is flexiblysupported to permit displacement thereof when a load is placed thereonto prevent possible damage to the sprinklerv head.

Although the present invention has been described in conjunction with apreferred embodiment, it will be obvious that various modifications indetail and arrangement may be made without departing from the spirit andcharacteristic thereof as defined by the scope of an inner tubetelescoped within said outer tube and projecting upwardly and outwardlythrough an opening in said cap, said inner tube carrying a sprinklerhead on its upper end;

sealing means for providing a watertight seal between said inner tubeand said cap while permitting axial movement and rotation of said innertube within said outer tube;

a helical spring concentrically arranged within said outer tube andsurrounding said inner tube, the lower end of said spring being fixed tosaid outer tube to prevent rotational or axial movement of said lowerend of said spring, the upper end of said spring abutting the undersideof said cap but being free of any connection with said cap or said outertube said spring functioning as a female thread; male thread means proecting laterally outwardly rotation said inner tube normally causingsaid male thread means to advance upwardly or downwardly along saidspring, depending upon the direction of rotation, thereby to adjust thevertical height of said inner tube relative to said outer tube.

2. In the riser mechanism as defined in claim 1, in which the upper endof said compression spring is free to deflect axially downwardly withinsaid outer tube, said spring being free to flex upon displacement ofsaid sprinkler head when subjected to a load, with the parts being sodimensioned that the upper end of said spring allows the projecting pinto slide freely past it downwardly when the inner tube is pushed downfrom its extreme upper most position.

3. In a sprinkler head'riser mechanism comprising an outer tube and aninner tube telescoped therein and carrying a sprinkler head on its upperend, wherein a threaded connection is provided between male threads onsaid inner tube and female threads in the form of a helical springconcentrically surrounding said inner tube within and fixed to saidouter tube, the improved method for adjusting the normal height of thesprinkler head which comprises:

rotating said inner tube, thereby to cause said inner tube to advance orretract within said outer tube as said male threads travel along saidspring.

1. A vertically adjustable sprinkler head riser mechanism comprising: avertically arranged outer tube having a cap sealing its upper end; aninner tube telescoped within said outer tube and projecting upwardly andoutwardly through an opening in said cap, said inner tube carrying asprinkler head on its upper end; sealing means for providing awatertight seal between said inner tube and said cap while permittingaxial movement and rotation of said inner tube within said outer tube; ahelical spring concentrically arranged within said outer tube andsurrounding said inner tube, the lower end of said spring being fixed tosaid outer tube to prevent rotational or axial movement of said lowerend of said spring, the upper end of said spring abutting the undersideof said cap but being free of any connection with said cap or said outertube, said spring functioning as a female thread; male thread meansprojecting laterally outwardly from said inner tube adjacent its lowerend and dimensioned to fit into the gap between adjacent coils of saidspring, said inner tube being vertically supported and positioned by theengagement of said male thread means with said spring, but said springotherwise normally exerting no force on said inner tube; rotation saidinner tube normally causing said male thread means to advance upwardlyor downwardly along said spring, depending upon the direction ofrotation, thereby to adjust the vertical height of said inner tuberelative to said outer tube.
 2. In the riser mechanism as defined inclaim 1, in which the upper end of said compression spring is free todeflect axially downwardly within said outer tube, said spring beingfree to flex upon displacement of said sprinkler head when subjected toa load, with the parts being so dimensioned that the upper end of saidspring allows the projecting pin to slide freely past it downwardly whenthe inner tube is pushed down from its extreme upper most position. 3.In a sprinkler head riser mechanism comprising an outer tube and aninner tube telescoped therein and carrying a sprinkler head on its upperend, wherein a threaded connection is provided between male threads onsaid inner tube and female threads in the form of a helical springconcentrically surrounding said inner tube within and fixed to saidouter tube, the improved method for adjusting the normal height of thesprinkler head which comprises: rotating said inner tube, thereby tocause said inner tube to advance or retract within said outer tube assaid male threads travel along said spring.